1. Field of the Invention
The present invention relates to an information presentation apparatus and method for presenting information in a virtual environment, in which a user can feel presence as actual space.
2. Description of the Related Art
In a museum, a panel of explanation of exhibition is located near to the exhibition of object itself. For example, in case of fossil of ammonite, the fossil is located in a glass show case and a panel of explanation of the ammonite is located upper to the glass show case. However, in this exhibition, the user can not imagine that the ammonite is one kind of big shell swimming in the sea in the Mesozoic era. In addition to this, a visitor often loses interest in the exhibition because watching method of the visitor is passive.
In order to solve this problem, recently, environment situation in which the ammonite is living is represented using computer graphics. In comparison with exhibition method of panel, the user can imagine the situation of the ammonite's life when he watches an exhibition of VTR. However, in the exhibition method of VTR, the watching method of the visitor is also passive. Information presented by VTR is predetermined. Therefore it is necessary to present document information using panel in same way of prior art.
Information presentation method to record in CD-ROM instead of VTR is used. In this information presentation method, for example, when the user selects the ammonite swimming in the sea by mouse, explanation of the ammonite is displayed on screen or sound narration of the ammonite is outputted through speaker. In comparison with the information presentation method of VTR, the watching method of the visitor is active because he can select his desired object. However in the information presentation method of CD-ROM, camera position of each scene and development of the scene are predetermined. Therefore, the visitor can not watch the scene from his/her desired position and change the position of the object in virtual environment.
In order to watch the object from the user's desired position and change location of the object in space, recently, a virtual environment is constructed in three dimensional virtual space using three dimensional computer graphics (CG). In the virtual environment using three dimensional CG, the user's view position and movement direction are indicated using a two dimensional or three dimensional pointing device. For example, as for the user's view position, a magnetic sensor is attached to a head of the visitor and the view position is controlled according to the coordinate value detected from the magnetic sensor. However, in this method, there are two problems. First, the magnetic sensor is too expensive. Second, the user can not understand his/her relative position in the virtual environment when the position of the user's head changes largely and protrudes out of the display.
Therefore, a method for determining movement and view point by one indication device is considered. However, in case of method for changing a mode to indicate move destination and a mode to indicate view point, after the user's position is moved in the virtual environment by one indication device, the user's view point is changed by the same indication device. This two step operation is complicated. In case of operation of two steps without changing mode, it often happens that both move destination and the view point are changed though the user changed only the move destination. In short, change of move and change of view point affect each other. Additionally, in case the view point is fixed, the view point can not turn to the object though the user's position comes near to the object in the virtual space. In this way, in the information presentation method of the virtual environment using dimensional CG, it is impossible to control the move direction in the virtual environment in connection with the view point.
On the other hand, in case drawing speed of the virtual environment is sufficiently high, the user can easily operate his virtual position to move near to the object.
However, in case of indicating move in the virtual environment through communication system from a remote place, drawing speed is low because of transmission delay. Accordingly, it often happens that the user mistakenly understands his/her move indication being insufficient and he/she inputs superfluous indication of move. As a result, the user's virtual position can not reach his/her destination in the virtual environment. In such case, it is necessary to restrict the move of the user's virtual position to easily come near the destination. However, if the restriction is too strict, the user's virtual position can not freely move in the virtual environment.
Furthermove, another presentation method for displaying the virtual environment on a large screen in front of many visitors is used. In this method, if one visitor selects an object to display an explanation of the object, the explanation displayed on the screen blocks other visitor's view. Additionally, the visitors can know the situation of the object's life in the virtual environment. However, they can not actually understand the weight of the object or a sense of touch of the object.